Ok I have a 98 Cobra with an Auburn diff and 4.30 gears. For a while now the gears have been "howling" they howl only when cruising (barely giving it throttle at about 40mph +. The noise is so loud it drowns out the exhaust while cruising. If I give it more gas or completely let off the throttle the noise goes away. Anyway, lately I've been hearing and feeling a clunking sound/feeling from the rear end only at very low speeds while turning. I started doing some investigating in the rear end and when I drained it the fluid that came out was a greyish metallic color. I don't mean metallic like it had metal shavings in it, it was very uniform in color but I've never seen any gear oil look like that. The diff drain plug is magnetic and did have some metal shavings on it. Any thoughts on what might be going on would be greatly appreciated.